Edema and Rheumatoid Arthritis

Intermittent Peripheral Edema

Ankle edema.
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Edema is defined as swelling caused by excessive fluid retention -- primarily water and sodium which get trapped in the body's tissues. Edema is usually associated with the venous or lymphatic systems. As edema develops, tiny blood vessels (capillaries) leak fluid into surrounding tissue. The leakage can be caused by injury or damage to the capillaries or by increased pressure. To compensate for fluid loss in the capillaries, the kidneys accumulate increased amounts of salt and water.

Circulation of blood increases. This causes more leakage of fluid from the capillaries -- and swelling worsens.

While edema can develop suddenly, it usually develops gradually and can be barely noticeable at first. It can occur as generalized edema or localized edema. Symptoms of edema are associated with the underlying cause. It's important to determine the underlying condition. There are a few different types of edema. The type of edema that occurs in the feet, ankles, legs, hands, and arms is known as peripheral edema. 

What May Cause Edema in the Extremities?

Edema is common with rheumatoid arthritis as a result of active inflammatory synovitis. Rheumatoid vasculitis with peripheral neuropathy (damage to the peripheral nerves) may be another cause. Swelling of the ankle and calf may be indicative of phlebitis (inflammation of a vein) or blockage of the lymphatic system (lymphedema), torn calf muscle with bleeding, as well as other general medical conditions (i.e., heart failure, kidney disease).

Certain medications, including NSAIDs and steroids which may be used to treat arthritis, can cause edema.

Edema in the extremities is often classified as pitting or non-pitting edema. Pitting edema describes when an indentation in the skin persists after pressure is applied and removed from the swollen area.

Pitting edema is not considered a specific feature of rheumatoid arthritis. Sometimes, in severe flare ups of rheumatoid arthritis, edema may develop in the hands secondary to a more widespread inflammatory process. In rare cases, non-pitting lymphedema can develop secondary to the rheumatoid disease process.

Also, a condition referred to as RS3PE, a subset of seronegative, symmetrical polyarthritis, is characterized by pitting edema of the hands. It's rare and was first described in 1985. RS3PE is short for remitting seronegative symmetrical synovitis with pitting edema. Psoriatic arthritis also may be associated with pitting edema. In cases associated with psoriatic arthritis, the pitting edema may involve tenosynovial structures (tendon and its sheath) or lymphatic vessels.     

The Bottom Line

Since edema can be a symptom of many serious medical problems, it is important to be evaluated by your doctor to determine the cause.

Sources:

Two cases of distal extremity swelling with pitting oedema in psoriatic arthritis: the different pathological mechanisms. Rheumatology International. Quarta L. et a. August 2010.
http://www.ncbi.nlm.nih.gov/pubmed/19609527

Polyarthritis and pitting oedema. Dudler J. et al. Annals of the Rheumatic Diseases. 1999.
http://ard.bmj.com/content/58/3/142.full

Edema. Diseases and Conditions. Cleveland Clinic. Accessed 01/24/16.
https://my.clevelandclinic.org/health/diseases_conditions/hic_Edema

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